Physicochemical characterization of diclofenac sodium-loaded poloxamer gel as a rectal delivery system with fast absorption

Rectal poloxamer gel systems composed of poloxamers and bioadhesive polymers were easy to administer to the anus and were mucoadhesive to the rectal tissues without leakage after the dose. However, a poloxamer gel containing diclofenac sodium could not be developed using bioadhesive polymers, since the drug was precipitated in this preparation. To develop a poloxamer gel using sodium chloride instead of bioadhesive polymers, the physicochemical properties such as gelation temperature, gel strength, and bioadhesive force of various formulations composed of diclofenac sodium, poloxamers, and sodium chloride were investigated. Furthermore, the pharmacokinetic study of diclofenac sodium delivered by the poloxamer gel was performed. Diclofenac sodium significantly increased the gelation temperature and weakened the gel strength and bioadhesive force, while sodium chloride did the opposite. The poloxamer gels with less than 1.0% sodium chloride, in which the drug was not precipitated, were inserted into the rectum without difficulty and leakage, and were retained in the rectum of rats for at least 6 hr. Furthermore, poloxamer gel gave significantly higher initial plasma concentrations and faster Tmax of diclofenac sodium than did solid suppository, indicating that drug from poloxamer gel could be absorbed faster than that from the solid one in rats. Our results suggested that a rectal poloxamer gel system with sodium chloride and poloxamers was a more physically stable, convenient, and effective rectal dosage form for diclofenac sodium.

Topical therapy for actinic keratoses, II: Diclofenac, colchicine, and retinoids

Actinic keratoses (AKs) are evolving, malignant cutaneous neoplasms. AKs can be treated with physical or destructive methods and by topical therapies. This article is the second in a 2-part series of current topical therapeutic options for AKs and discusses topical diclofenac, colchicine, and retinoids. The first part focused on topical 5-fluorouracil and imiquimod.

Low-dose diclofenac potassium in the treatment of episodic tension-type headache

BACKGROUND

Several clinical trials have demonstrated that low doses of non-steroidal anti-inflammatory drugs relieve episodic tension-type headache (ETH).

AIMS

The aims of this placebo-controlled study were to determine whether single doses of diclofenac-K 12.5 and 25mg effectively relieve ETH in adults and to compare it to ibuprofen 400mg.

METHODS

A single-dose multicentre, randomised, double-blind, double-dummy, clinical trial was conducted at 22 primary care centres in Germany. All subjects had a history of ETH according to the classification of the International Headache Society. Of 684 subjects randomised, 620 used the study drugs for an episode of tension headache occurring within one month after enrolment: diclofenac-K 12.5mg (n=160), diclofenac-K 25mg (n=156), ibuprofen 400mg (n=151) and placebo (n=153). The primary efficacy variable was total pain relief, calculated as the time-weighted sum of the pain relief assessments from baseline to the 3h evaluation time (TOTPAR-3).

RESULTS

For TOTPAR-3, all active treatments were superior to placebo; no statistically significant difference between the three active treatments could be detected. A similar pattern was also observed with regard to TOTPAR-6 (6h evaluation time), > or =50%maxTOTPAR at 3 and 6h, weighted pain intensity difference at 3 and 6h (SPID-3; SPID-6), percentage of patients with complete headache relief at 2h, end of study global evaluation and time to rescue medication. The number-needed-to-treat (NNT) at 6h was 4.5 (2.9-9.2) in the ibuprofen 400mg group, 4.0 (2.8-7.3) in the diclofenac-K 12.5mg group and 3.9 (2.7-7.1) in the diclofenac-K 25mg group. These differences were not statistically significant.

CONCLUSION

Diclofenac-K, administered as single doses of 12.5 and 25mg effectively relieves ETH and is comparable to ibuprofen 400mg.

Radiofrequency-driven skin microchanneling as a new way for electrically assisted transdermal delivery of hydrophilic drugs

The aim of this study was to increase the skin penetration of two drugs, granisetron hydrochloride and diclofenac sodium, using a microelectronic device based on an ablation of outer layers of skin using radiofrequency high-voltage currents. These radiofrequency currents created an array of microchannels across the stratum corneum deep into the epidermis. The percutaneous penetration studies were first performed in vitro using excised full thickness porcine ear skin. An array of 100 microelectrodes/cm(2) was used in these studies. The skin permeability of both molecules was significantly enhanced after pretreatment with the radiofrequency microelectrodes, as compared to the delivery through the untreated control skin. Steady state fluxes of 41.6 micro g/cm(2)/h (r=0.997) and 23.0 micro g/cm(2)/h (r=0.989) were obtained for granisetron and diclofenac, respectively. The enhanced transdermal delivery was also demonstrated in vivo in rats. It was shown that diclofenac plasma levels in the pretreated rats reached plateau levels of 1.22+/-0.32 micro g/ml after 3 h to 1.47+/-0.33 micro g/ml after 6 h, as compared to 0.16+/-0.04 micro g/ml levels obtained after 6 h in untreated rats. Similarly, application of granisetron patches (3% in crosslinked hydrogel) onto rats' abdominal skin pretreated with radiofrequency electrodes resulted in an averaged peak plasma level of 239.3+/-43.7 ng/ml after 12 h, which was about 30 times higher than the plasma levels obtained by 24-h passive diffusion of the applied drug. The results emphasize, therefore, that the new transdermal technology is suitable for therapeutic delivery of poorly penetrating molecules.

Estimation of absorption parameters from the non-steady-state phase in the rat gut perfusion model

The aim of the study was to calculate absorption parameters, including permeability coefficients (P(app)), from the non-steady-state portion of the outflow to inflow concentration ratio vs time profiles and compare them with those obtained via the more traditionally used steady-state phase. The rat in-situ intestinal perfusion method was used. The compounds studied, diclofenac and macrogol 4000 (polyethylene glycol (PEG) 4000), were perfused at four different flow rates (0.1-2.0 mL min(-1)). The estimates of P(app) from the non-steady-state data were systematically lower for both compounds. The non-steady-state analysis gave estimates of the intestinal radius, r. The internal diameter of the intestine segment increased as the flow rate increased. When this effect was taken into account similar P(app) estimates were obtained by the two approaches. Thus the convention of using a constant value of intestinal radius in the steady-state equation leads to an over estimate of the P(app) when high flow rates are employed. The different trends observed, between P(app) and perfusate flow rate, for the two compounds, macrogol 4000 and diclofenac, may be linked to increased surface area and exposure to membrane pores of larger size. The longitudinal spreading coefficient, De, increased with flow rate and was approximately 1000 times greater than that estimated for molecular diffusion. The high values obtained were consistent with the non-smooth biological surface and peristaltic movement present in-vivo.

Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit vascular smooth muscle cell proliferation via differential effects on the cell cycle

Abnormal vascular smooth muscle cell (VSMC) proliferation plays an important role in the pathogenesis of both atherosclerosis and restenosis. Recent studies suggest that high-dose salicylates, in addition to inhibiting cyclooxygenase activity, exert an antiproliferative effect on VSMC growth both in-vitro and in-vivo. However, whether all non-steroidal anti-inflammatory drugs (NSAIDs) exert similar antiproliferative effects on VSMCs, and do so via a common mechanism of action, remains to be shown. In this study, we demonstrate that the NSAIDs aspirin, sodium salicylate, diclofenac, ibuprofen, indometacin and sulindac induce a dose-dependent inhibition of proliferation in rat A10 VSMCs in the absence of significant cytotoxicity. Flow cytometric analyses showed that exposure of A10 cells to diclofenac, indometacin, ibuprofen and sulindac, in the presence of the mitotic inhibitor, nocodazole, led to a significant G0/G1 arrest. In contrast, the salicylates failed to induce a significant G1 arrest since flow cytometry profiles were not significantly different from control cells. Cyclin A levels were elevated, and hyperphosphorylated p107 was present at significant levels, in salicylate-treated A10 cells, consistent with a post-G1/S block, whereas cyclin A levels were low, and hypophosphorylated p107 was the dominant form, in cells treated with other NSAIDs consistent with a G1 arrest. The ubiquitously expressed cyclin-dependent kinase (CDK) inhibitors, p21 and p27, were increased in all NSAID-treated cells. Our results suggest that diclofenac, indometacin, ibuprofen and sulindac inhibit VSMC proliferation by arresting the cell cycle in the G1 phase, whereas the growth inhibitory effect of salicylates probably affects the late S and/or G2/M phases. Irrespective of mechanism, our results suggest that NSAIDs might be of benefit in the treatment of certain vasculoproliferative disorders.

Efficacy of topical nonsteroidal antiinflammatory drugs in mastalgia treatment

BACKGROUND

The aim of the study was to investigate the effects of topical nonsteroidal antiinflammatory drugs (NSAIDs) on mastalgia.

STUDY DESIGN

A prospective, randomized, blinded, placebo-controlled study was performed to evaluate the effects of topical NSAIDs on cyclic and noncyclic mastalgia. A total of 108 patients, 60 with cyclic (group I) and 48 with noncyclic (group II) breast pain were enrolled. Patients within each group were randomly assigned to receive either topical NSAIDs or placebo three times daily for at least 6 months. Severity of pain was measured before and after 6 months of treatment.

RESULTS

The pain score decreased significantly when the mean initial breast pain score was compared with the sixth-month breast pain score of the treatment or the placebo group of cyclic (p = 0.0001 and p = 0.0001, respectively) or noncyclic mastalgia (p = 0.0001 and p = 0.0001, respectively). Significant differences were found when the mean within-person change in pain values in each treatment group were compared with the change in the respective placebo group for either cyclic or noncyclic mastalgia (p = 0.0001 and p = 0.0001, respectively). Changes in pain within treatment groups or placebo groups for cyclic versus noncyclic mastalgia were not found to be statistically different (p = 0.53 and p = 0.96, respectively). No side effect was seen in any group.

CONCLUSIONS

Topical application of NSAIDs was effective in both cyclic and noncyclic mastalgia with minimal side effects.

Fever induction by localized subcutaneous inflammation in guinea pigs: the role of cytokines and prostaglandins

In guinea pigs, dose-dependent febrile responses can be induced by injection of a high (100 micro g/kg) or low (10 micro g/kg) dose of bacterial lipopolysaccharide (LPS) into artificial subcutaneously implanted Teflon chambers. In this fever model, LPS does not enter the systemic circulation from the site of localized tissue inflammation in considerable amounts but causes a local induction of the proinflammatory cytokines tumor necrosis factor (TNF) and interleukin-6 (IL-6), which can be measured in lavage fluid collected from the chamber area. Only in response to the high LPS dose, small traces of TNF are measurable in blood plasma. A moderate increase of circulating IL-6 occurs in response to administration of both LPS doses. To investigate the putative roles of TNF and prostaglandins in this fever model, a neutralizing TNF binding protein (TNF-bp) or a nonselective inhibitor of cyclooxygenases (diclofenac) was injected along with the high or low dose of LPS into the subcutaneous chamber. In control groups, both doses of LPS were administered into the chamber along with the respective vehicles for the applied drugs. The fever response to the high LPS dose remained unimpaired by treatment with TNF-bp despite an effective neutralization of bioactive TNF in the inflamed tissue area. In response to the low LPS dose, there was an accelerated defervescence under the influence of TNF-bp. Blockade of prostaglandin formation with diclofenac completely abolished fever in response to both LPS doses. In conclusion, prostaglandins seem to be essential components for the manifestation of fever in this model.

Preservative-free diclofenac sodium 0.1% for vernal keratoconjunctivitis

PURPOSE

The aim of this study is to evaluate the efficacy of prolonged treatment with preservative-free diclofenac sodium 0.1% eye drops in patients with vernal keratoconjunctivitis (VKC).

METHODS

A prospective open study was performed in 22 patients with VKC treated with preservative-free diclofenac sodium 0.1% eye drops. Patients used the eye drops four times daily in both eyes for 120 days. Signs (papillae, hyperaemia and corneal lesions) and symptoms (itching, redness and photophobia) of the ocular surface were graded and statistically evaluated before and after treatment by a non-parametric test (Mann-Whitney U-test).

RESULTS

Forty per cent of the patients showed an improvement in their symptoms at the end of the treatment. Total signs and symptoms scores were significantly decreased at the end of treatment compared with the baseline values (from 6.13+/-1.45 to 0.81+/-0.90 and from 5.40+/-1.18 to 2.63+/-0.95, respectively; P<0.001). Significant decreases in conjunctival redness (P<0.001), itching (P<0.001) and photophobia (P<0.001 ) were observed at the end of treatment. Conjunctival hyperaemia was significantly reduced (P<0.001) at the end of treatment, while no significant differences were observed for corneal lesions and for papillary size. No patient showed exacerbation of the disease during the treatment.

CONCLUSION

VKC is a chronic disease that requires prolonged treatment to control the inflammatory process. Our preliminary study demonstrates the efficacy and safety of preservative-free diclofenac sodium 0.1% eye drops in controlling the signs and symptoms of VKC in prolonged treatment.

Topical diclofenac patch in patients with knee osteoarthritis: a randomized, double-blind, controlled clinical trial

OBJECTIVE

To assess the efficacy and safety of a diclofenac hydroxyethylpyrrolidine (DHEP) patch in the treatment of symptomatic osteoarthritis (OA) of the knee joint.

METHODS

A double-blind, randomised, placebo-controlled trial was carried out on 103 outpatients for 2 weeks. The main efficacy parameters were spontaneous pain and Lequesne's Index. Secondary endpoints were walking time over a standard distance, global assessment of efficacy and tolerability, and paracetamol consumption.

RESULTS

The active treatment group showed a significant improvement in pain, Lequesne's Index, and the physician's and patient's global assessment of efficacy. For these parameters the difference between groups was statistically significant in favour of the DHEP patch. Adverse reactions were seen in a small number of probands and were similar in both groups.

CONCLUSIONS

The results of this trial suggest that the DHEP patch appears to be an effective and safe treatment for patients suffering from symptomatic knee OA.

Topical diclofenac in hyaluronan gel for the treatment of solar keratoses

This randomized, double-blind, placebo-controlled study assessed the efficacy and safety of a topical gel containing 3% diclofenac in 2.5% hyaluronan in 150 patients with solar keratoses (SK). The active treatment was compared with the vehicle only, hyaluronan gel, as placebo over a 12-week period. Patients in both groups applied the active treatment or placebo to a targeted area of skin (0.25 g b.d.). At 12 weeks the mean lesion-count reduction in the targeted area was not significantly different between treatments. However, at post-termination follow up (16 weeks), there was a highly significant decrease in the number of lesions, 6.2 +/- 7.5 standard deviations (SD) (56.1% reduction) in the active treatment group compared with 2.4 +/- 4.3 SD (23.6% reduction) in the placebo group (P < 0.001). Other efficacy measures (complete lesion resolution, >50% lesion reduction) were also significantly different (P < 0.01) between treatments at 16 weeks. In conclusion, topical 3% diclofenac in 2.5% hyaluronan gel was effective and well tolerated in this study, suggesting a role for this therapy in the treatment of SK.

Physicochemical characterization and in vivo evaluation of thermosensitive diclofenac liquid suppository

Liquid suppository systems composed of poloxamers and bioadhesive polymers were easy to administer to the anus and mucoadhesive to the rectal tissues without leakage after the dose. However, a liquid suppository containing diclofenac sodium could not be developed using bioadhesive polymers, since the drug was precipitated in this preparation. To develop a liquid suppository system using sodium chloride instead of bioadhesive polymers, the physicochemical properties such as gelation temperature, gel strength and bioadhesive force of various formulations composed of diclofenac sodium, poloxamers and sodium chloride were investigated. Furthermore, the pharmacokinetic study of diclofenac sodium delivered by the liquid suppository was performed. Diclofenac sodium significantly increased the gelation temperature and weakened the gel strength and bioadhesive force, while sodium chloride did the opposite. The liquid suppositories with less than 1.0% of sodium chloride, in which the drug was not precipitated, were inserted into the rectum without difficulty and leakage. Furthermore, liquid suppository gave significantly higher initial plasma concentrations and faster Tmax of diclofenac sodium than did solid suppository, indicating that drug from liquid suppository could be absorbed faster than that from solid one in rats. Our results suggested that a thermosensitive liquid suppository system with sodium chloride and poloxamers was a more physically stable, convenient and effective rectal dosage form for diclofenac sodium.

A study of co-treatment of nonsteroidal anti-inflammatory drugs (NSAIDs) with misoprostol for cervical priming before suction termination of first trimester pregnancy

This double-blind randomized control study was conducted to evaluate whether a nonsteroidal anti-inflammatory drug (NSAID) could act as an effective pain control method during first trimester suction abortion, and whether co-treatment of NSAID with misoprostol will decrease the efficacy of the cervical ripening effect of misoprostol. Subjects were randomized to receive misoprostol alone or misoprostol together with diclofenac sodium. Both groups of subjects suffered from similar incidence of preoperative side effects. Co-treatment of NSAID with misoprostol did not attenuate the cervical ripening efficacy of misoprostol. There was no significant pain reduction in the group treated with NSAID, except that a marginal benefit was found in the subgroup of multiparous women. About two thirds of the subjects in both treatment groups found that this was a satisfactory pain relief method during the procedure.

Four analgesic techniques for shockwave lithotripsy: eutectic mixture local anesthetic is a good alternative

BACKGROUND AND PURPOSE

Various sedative and analgesic medication has been used for shockwave lithotripsy (SWL). The aim of this study was to evaluate the efficacy of different anesthesia modalities in these patients.

PATIENTS AND METHODS

One hundred patients were randomly divided into four groups. The first (Group F) received fentanyl 1 microg/kg intravenously (IV), the second (Group D) received diclofenac sodium 1 mg/kg intramuscularly (IM), the third (Group T) received tramadol 1.5 mg/kg IM, and the fourth (Group E) was given 15 g of eutectic mixture local anesthetic (EMLA) cream containing lidocaine and prilocaine. After routine preoperative evaluation, all patients received midazolam 2 mg IV 5 minutes before lithotripsy for sedative premedication. In all groups, a supplemental 25-microg bolus of fentanyl was administered IV when patients complained of pain, moved, or grimaced in response to the shockwaves. Pain intensity was evaluated on a 0- to 100-mm visual analog scale (VAS). The level of sedation was determined using the Observer's Assessment of Alertness/Sedation (OAS/S). Side effects such as bradypnea, oxygen desaturation, bradycardia, pruritus, and nausea and vomiting were recorded.

RESULTS

There were no statistically significant differences among the four groups with regard to VAS, OAS/S scores, or side effects. In Group F, the mean arterial pressure was decreased significantly at 10 and 20 minutes. The patients in this group also manifested a decrease of oxygen saturation at the first, tenth, and twentieth minutes and the end of SWL.

CONCLUSION

Application of EMLA cream was as safe and effective as fentanyl, diclofenac, and tramadol, and reduction of the fentanyl dose during SWL was possible.

A multicenter, randomized, double-blind, double-dummy, placebo- and active-controlled, parallel-group comparison of diclofenac-K and ibuprofen for the treatment of adults with influenza-like symptoms

BACKGROUND

The alleviation of influenza-like symptoms, such as fever, headache, and muscle/joint aches and pains, is important so that sufferers can return to their normal daily activities. A flexible dosing regimen is proposed, starting with an initial dose of 2 tablets (2 x 12.5 mg), followed by 1 to 2 tablets every 4 to 6 hours as needed, to a maximum daily dose of 75 mg for up to 3 days for fever and 5 days for pain. This flexible dosing regimen matches the existing over-the-counter dosing regimen of ibuprofen, which allows the patient to adjust the treatment according to the type, duration, and severity of symptoms.

OBJECTIVE

This study assessed the efficacy and tolerability of diclofenac-K 12.5 mg versus ibuprofen 200 mg and placebo against influenza-like symptoms (oral temperature > or = 38.1 degrees C, and at least moderate headache and muscle/joint aches and pains).

METHODS

This was a 3-day, multicenter, randomized, double-blind, double-dummy, placebo- and active-controlled, parallel-group trial conducted in Germany. The flexible dosing regimens comprised 2 tablets of diclofenac-K (12.5 mg), ibuprofen (200 mg), or placebo, then 1 to 2 tablets every 4 to 6 hours as needed, to a maximum of 6 tablets/d. Primary efficacy outcomes were fever reduction after the initial dose and an end-of-study global assessment of overall symptom relief. Secondary efficacy outcomes included reduction of feverishness; relief of headache; and relief of muscle/joint aches and pains, after the first dose and at the end of days 1, 2, and 3. Use of rescue medication (paracetamol 500-mg tablets) and usage patterns of study medication were also studied. Tolerability was monitored by recording of patients' adverse events.

RESULTS

A total of 356 patients were enrolled (n = 121, 120, and 115 patients in the diclofenac-K, ibuprofen, and placebo groups, respectively). All patients were white except 1 Asian patient in the diclofenac-K group; 55% to 60% of patients in all 3 groups were male; the mean age in each treatment group was approximately 40 years. At baseline, mean oral temperature ranged from 38.65 degrees C in the placebo group to 38.74 degrees C in the diclofenac-K group. Mean oral temperatures in both active groups were significantly lower than that of the placebo group from 30 minutes through 6 hours (P < 0.001), dropping 0.85 degrees C after 4 hours in the diclofenac-K group and 0.76 degrees C in the ibuprofen group versus 0.32 degrees C for placebo. In the end-of-study global treatment assessment, 89.0% of diclofenac-K and 89.1% of ibuprofen patients rated global efficacy as "good" to "excellent" versus only 32.1% for placebo. Diclofenac-K was superior to placebo (P < 0.001) and similar to ibuprofen on all direct assessments of fever and aches and pains. Both active treatments were as well tolerated as was placebo.

CONCLUSIONS

In this 3-day study, diclofenac-K 12.5 mg taken in a flexible dosing regimen was more effective than placebo in relieving influenza-like symptoms, with comparable tolerability Efficacy and tolerability of diclofenac-K were similar to those of ibuprofen 200 mg.

Histometric study of socket healing after tooth extraction in rats treated with diclofenac

The purpose of the present study was to investigate if diclofenac administration interferes with the time course of alveolar wound healing in rats. Forty-two Wistar rats were used, 21 rats received 10 mg/kg/day of diclofenac one day before and 4 days after extraction of the right maxillary incisors and 21 rats received saline. The animals were sacrificed 7, 14 and 21 days after tooth extraction. Progressive new bone formation and a decrease in the volume fraction of blood clot and connective tissue from 1 to 3 weeks after tooth extraction was quantified using the histometric point-counting method. Diclofenac treatment caused a significant delay in new bone formation in association with an impairment of blood clot remission/organization.

[Effectiveness of ketonal and diclofenac in spondylarthrosis complicated with spinal pain]

The article compares efficacy and safety of ketonal used in a dose 300 mg/day and diclofenac in a dose 150 mg/day in patients with primary spinal pain. The treatment of 60 patients aged 35 to 70 years (mean age 42.7 +/- 12.4 years) showed high efficacy of ketonal in spinal pain and low rate of side effects induced by this drug. Diclofenac was also effective.

Analgesic efficacy of low-dose diclofenac versus paracetamol and placebo in postoperative dental pain

AIMS

To compare the efficacy and safety of diclofenac-K (12.5 mg) vs paracetamol (500 mg) and placebo given in a flexible dosage regimen to treat pain resulting from extraction of impacted third molar teeth.

METHODS

This was a 2-day, double-blind, double-dummy, randomized, parallel-group, placebo-controlled study of diclofenac-K (12.5 mg) tablets vs paracetamol (500 mg) tablets and placebo in patients with moderate or severe pain within 8 hours of extraction of impacted third molars.

RESULTS

After the first 2-tablet dose, patients took on average 2.5 additional tablets of diclofenac-K or 2.4 tablets of paracetamol, almost all as 1-tablet doses. Most placebo patients discontinued by taking rescue medication (ibuprofen 200 mg) on the first day. Pain relief after the initial dose of diclofenac-K (2 x 12.5 mg) was superior to placebo (P < .01 for all efficacy outcomes) and comparable to paracetamol (2 x 500 mg). About 30% of patients in each active treatment group took rescue medication during the study, compared to 78% on placebo. About 70% in each active treatment group considered the overall pain relief to be "some," "a lot," or "complete" compared to only 15% on placebo. The incidence of adverse events in each active treatment group was low and comparable between the treatments.

CONCLUSION

An initial double-dose of diclofenac-K (2 x 12.5 mg) or paracetamol (2 x 500 mg) adequately relieved the most intense postoperative pain, and the flexible multiple dose regimen (1 or 2 tablets) maintained adequate pain relief thereafter. Most patients needed only 1-tablet doses following the initial 2-tablet dose.